EP1827656 discloses a power plant with two gas turbine engines in a tandem arrangement and a CO2 capture system.
In particular, a first engine is fed with fresh air and fuel and its flue gases are fed into a second engine together with fuel. The second engine is fed with the flue gases from the first engine and fuel; the flue gases from the second engine are then fed to the CO2 capture system.
This configuration allows an increase of the CO2 concentration in the flue gases supplied to the CO2 capture system and, thus, makes the CO2 capture system and its operation cheaper.
Nevertheless, during operation of the described power plant load regulation could be troubling.
Load regulation could cause the composition of the flue gases from the first engine to change or the requirements of the hot gases circulating within the second engine to change (the hot gases circulating within the second engine correspond to the flue gases discharged from the first engine).
When one or both of the above circumstances happen, combustion in the combustion chamber of the first and/or second engine could occur under non-optimal conditions.